In recent years, access points of public wireless LANs have been put in place. In a case of accessing a network outside home, use of a wireless LAN function of the portable communication terminal has been increased. Accordingly, wireless communication is performed between an access point or a wireless LAN switch (wireless LAN master device) installed in a wireless LAN communication spot, and the portable communication terminal (extension device), and an access to the Internet through the wireless LAN communication spot becomes available.
When the wireless communication is performed between the access point or the wireless LAN switch installed in the wireless LAN communication spot, and the portable communication terminal, the portable communication terminal is identified with communication terminal identification information such as a MAC address, and the wireless communication is performed. Therefore, in the wireless LAN communication spot, the portable communication terminal that is performing the wireless communication is managed with the communication terminal identification information. Patent Literature 1 describes an example of the wireless communication using the wireless LAN.